Top-secret documents reveal that the National Security Agency is dramatically expanding its ability to covertly hack into computers on a mass scale by using automated systems that reduce the level of human oversight in the process. The classified files – provided previously by NSA whistleblower Edward Snowden – contain new details about groundbreaking surveillance technology the agency has developed to infect potentially millions of computers worldwide with malware “implants.” The clandestine initiative enables the NSA to break into targeted computers and to siphon out data from foreign Internet and phone networks. The covert infrastructure that supports the hacking efforts operates from the agency’s headquarters in Fort Meade, Maryland, and from eavesdropping bases in the United Kingdom and Japan.